1 /*- 2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Portions of this software were developed under sponsorship from Snow 6 * B.V., the Netherlands. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 /* Add compatibility bits for FreeBSD. */ 34 #define PTS_COMPAT 35 /* Add pty(4) compat bits. */ 36 #define PTS_EXTERNAL 37 /* Add bits to make Linux binaries work. */ 38 #define PTS_LINUX 39 40 #include <sys/param.h> 41 #include <sys/lock.h> 42 #include <sys/condvar.h> 43 #include <sys/conf.h> 44 #include <sys/fcntl.h> 45 #include <sys/file.h> 46 #include <sys/filedesc.h> 47 #include <sys/filio.h> 48 #include <sys/kernel.h> 49 #include <sys/limits.h> 50 #include <sys/malloc.h> 51 #include <sys/poll.h> 52 #include <sys/proc.h> 53 #include <sys/resourcevar.h> 54 #include <sys/serial.h> 55 #include <sys/stat.h> 56 #include <sys/syscall.h> 57 #include <sys/syscallsubr.h> 58 #include <sys/sysctl.h> 59 #include <sys/sysent.h> 60 #include <sys/sysproto.h> 61 #include <sys/systm.h> 62 #include <sys/tty.h> 63 #include <sys/ttycom.h> 64 65 #include <machine/stdarg.h> 66 67 /* 68 * Our utmp(5) format is limited to 8-byte TTY line names. This means 69 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow 70 * users to increase this number, assuming they have manually increased 71 * UT_LINESIZE. 72 */ 73 static struct unrhdr *pts_pool; 74 75 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device"); 76 77 /* 78 * Per-PTS structure. 79 * 80 * List of locks 81 * (t) locked by tty_lock() 82 * (c) const until freeing 83 */ 84 struct pts_softc { 85 int pts_unit; /* (c) Device unit number. */ 86 unsigned int pts_flags; /* (t) Device flags. */ 87 #define PTS_PKT 0x1 /* Packet mode. */ 88 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */ 89 char pts_pkt; /* (t) Unread packet mode data. */ 90 91 struct cv pts_inwait; /* (t) Blocking write() on master. */ 92 struct selinfo pts_inpoll; /* (t) Select queue for write(). */ 93 struct cv pts_outwait; /* (t) Blocking read() on master. */ 94 struct selinfo pts_outpoll; /* (t) Select queue for read(). */ 95 96 #ifdef PTS_EXTERNAL 97 struct cdev *pts_cdev; /* (c) Master device node. */ 98 #endif /* PTS_EXTERNAL */ 99 100 struct uidinfo *pts_uidinfo; /* (c) Resource limit. */ 101 }; 102 103 /* 104 * Controller-side file operations. 105 */ 106 107 static int 108 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred, 109 int flags, struct thread *td) 110 { 111 struct tty *tp = fp->f_data; 112 struct pts_softc *psc = tty_softc(tp); 113 int error = 0; 114 char pkt; 115 116 if (uio->uio_resid == 0) 117 return (0); 118 119 tty_lock(tp); 120 121 for (;;) { 122 /* 123 * Implement packet mode. When packet mode is turned on, 124 * the first byte contains a bitmask of events that 125 * occured (start, stop, flush, window size, etc). 126 */ 127 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) { 128 pkt = psc->pts_pkt; 129 psc->pts_pkt = 0; 130 tty_unlock(tp); 131 132 error = ureadc(pkt, uio); 133 return (error); 134 } 135 136 /* 137 * Transmit regular data. 138 * 139 * XXX: We shouldn't use ttydisc_getc_poll()! Even 140 * though in this implementation, there is likely going 141 * to be data, we should just call ttydisc_getc_uio() 142 * and use its return value to sleep. 143 */ 144 if (ttydisc_getc_poll(tp)) { 145 if (psc->pts_flags & PTS_PKT) { 146 /* 147 * XXX: Small race. Fortunately PTY 148 * consumers aren't multithreaded. 149 */ 150 151 tty_unlock(tp); 152 error = ureadc(TIOCPKT_DATA, uio); 153 if (error) 154 return (error); 155 tty_lock(tp); 156 } 157 158 error = ttydisc_getc_uio(tp, uio); 159 break; 160 } 161 162 /* Maybe the device isn't used anyway. */ 163 if (psc->pts_flags & PTS_FINISHED) 164 break; 165 166 /* Wait for more data. */ 167 if (fp->f_flag & O_NONBLOCK) { 168 error = EWOULDBLOCK; 169 break; 170 } 171 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx); 172 if (error != 0) 173 break; 174 } 175 176 tty_unlock(tp); 177 178 return (error); 179 } 180 181 static int 182 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred, 183 int flags, struct thread *td) 184 { 185 struct tty *tp = fp->f_data; 186 struct pts_softc *psc = tty_softc(tp); 187 char ib[256], *ibstart; 188 size_t iblen, rintlen; 189 int error = 0; 190 191 if (uio->uio_resid == 0) 192 return (0); 193 194 for (;;) { 195 ibstart = ib; 196 iblen = MIN(uio->uio_resid, sizeof ib); 197 error = uiomove(ib, iblen, uio); 198 199 tty_lock(tp); 200 if (error != 0) { 201 iblen = 0; 202 goto done; 203 } 204 205 /* 206 * When possible, avoid the slow path. rint_bypass() 207 * copies all input to the input queue at once. 208 */ 209 MPASS(iblen > 0); 210 do { 211 rintlen = ttydisc_rint_simple(tp, ibstart, iblen); 212 ibstart += rintlen; 213 iblen -= rintlen; 214 if (iblen == 0) { 215 /* All data written. */ 216 break; 217 } 218 219 /* Maybe the device isn't used anyway. */ 220 if (psc->pts_flags & PTS_FINISHED) { 221 error = EIO; 222 goto done; 223 } 224 225 /* Wait for more data. */ 226 if (fp->f_flag & O_NONBLOCK) { 227 error = EWOULDBLOCK; 228 goto done; 229 } 230 231 /* Wake up users on the slave side. */ 232 ttydisc_rint_done(tp); 233 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx); 234 if (error != 0) 235 goto done; 236 } while (iblen > 0); 237 238 if (uio->uio_resid == 0) 239 break; 240 tty_unlock(tp); 241 } 242 243 done: ttydisc_rint_done(tp); 244 tty_unlock(tp); 245 246 /* 247 * Don't account for the part of the buffer that we couldn't 248 * pass to the TTY. 249 */ 250 uio->uio_resid += iblen; 251 return (error); 252 } 253 254 static int 255 ptsdev_truncate(struct file *fp, off_t length, struct ucred *active_cred, 256 struct thread *td) 257 { 258 259 return (EINVAL); 260 } 261 262 static int 263 ptsdev_ioctl(struct file *fp, u_long cmd, void *data, 264 struct ucred *active_cred, struct thread *td) 265 { 266 struct tty *tp = fp->f_data; 267 struct pts_softc *psc = tty_softc(tp); 268 int error = 0, sig; 269 270 switch (cmd) { 271 case FIONBIO: 272 /* This device supports non-blocking operation. */ 273 return (0); 274 case FIONREAD: 275 tty_lock(tp); 276 if (psc->pts_flags & PTS_FINISHED) { 277 /* Force read() to be called. */ 278 *(int *)data = 1; 279 } else { 280 *(int *)data = ttydisc_getc_poll(tp); 281 } 282 tty_unlock(tp); 283 return (0); 284 case FIODGNAME: { 285 struct fiodgname_arg *fgn; 286 const char *p; 287 int i; 288 289 /* Reverse device name lookups, for ptsname() and ttyname(). */ 290 fgn = data; 291 p = tty_devname(tp); 292 i = strlen(p) + 1; 293 if (i > fgn->len) 294 return (EINVAL); 295 return copyout(p, fgn->buf, i); 296 } 297 298 /* 299 * We need to implement TIOCGPGRP and TIOCGSID here again. When 300 * called on the pseudo-terminal master, it should not check if 301 * the terminal is the foreground terminal of the calling 302 * process. 303 * 304 * TIOCGETA is also implemented here. Various Linux PTY routines 305 * often call isatty(), which is implemented by tcgetattr(). 306 */ 307 #ifdef PTS_LINUX 308 case TIOCGETA: 309 /* Obtain terminal flags through tcgetattr(). */ 310 tty_lock(tp); 311 *(struct termios*)data = tp->t_termios; 312 tty_unlock(tp); 313 return (0); 314 #endif /* PTS_LINUX */ 315 case TIOCSETAF: 316 case TIOCSETAW: 317 /* 318 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and 319 * TCSADRAIN into something different. If an application would 320 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may 321 * deadlock waiting for all data to be read. 322 */ 323 cmd = TIOCSETA; 324 break; 325 #if defined(PTS_COMPAT) || defined(PTS_LINUX) 326 case TIOCGPTN: 327 /* 328 * Get the device unit number. 329 */ 330 if (psc->pts_unit < 0) 331 return (ENOTTY); 332 *(unsigned int *)data = psc->pts_unit; 333 return (0); 334 #endif /* PTS_COMPAT || PTS_LINUX */ 335 case TIOCGPGRP: 336 /* Get the foreground process group ID. */ 337 tty_lock(tp); 338 if (tp->t_pgrp != NULL) 339 *(int *)data = tp->t_pgrp->pg_id; 340 else 341 *(int *)data = NO_PID; 342 tty_unlock(tp); 343 return (0); 344 case TIOCGSID: 345 /* Get the session leader process ID. */ 346 tty_lock(tp); 347 if (tp->t_session == NULL) 348 error = ENOTTY; 349 else 350 *(int *)data = tp->t_session->s_sid; 351 tty_unlock(tp); 352 return (error); 353 case TIOCPTMASTER: 354 /* Yes, we are a pseudo-terminal master. */ 355 return (0); 356 case TIOCSIG: 357 /* Signal the foreground process group. */ 358 sig = *(int *)data; 359 if (sig < 1 || sig >= NSIG) 360 return (EINVAL); 361 362 tty_lock(tp); 363 tty_signal_pgrp(tp, sig); 364 tty_unlock(tp); 365 return (0); 366 case TIOCPKT: 367 /* Enable/disable packet mode. */ 368 tty_lock(tp); 369 if (*(int *)data) 370 psc->pts_flags |= PTS_PKT; 371 else 372 psc->pts_flags &= ~PTS_PKT; 373 tty_unlock(tp); 374 return (0); 375 } 376 377 /* Just redirect this ioctl to the slave device. */ 378 tty_lock(tp); 379 error = tty_ioctl(tp, cmd, data, fp->f_flag, td); 380 tty_unlock(tp); 381 if (error == ENOIOCTL) 382 error = ENOTTY; 383 384 return (error); 385 } 386 387 static int 388 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred, 389 struct thread *td) 390 { 391 struct tty *tp = fp->f_data; 392 struct pts_softc *psc = tty_softc(tp); 393 int revents = 0; 394 395 tty_lock(tp); 396 397 if (psc->pts_flags & PTS_FINISHED) { 398 /* Slave device is not opened. */ 399 tty_unlock(tp); 400 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP); 401 } 402 403 if (events & (POLLIN|POLLRDNORM)) { 404 /* See if we can getc something. */ 405 if (ttydisc_getc_poll(tp) || 406 (psc->pts_flags & PTS_PKT && psc->pts_pkt)) 407 revents |= events & (POLLIN|POLLRDNORM); 408 } 409 if (events & (POLLOUT|POLLWRNORM)) { 410 /* See if we can rint something. */ 411 if (ttydisc_rint_poll(tp)) 412 revents |= events & (POLLOUT|POLLWRNORM); 413 } 414 415 /* 416 * No need to check for POLLHUP here. This device cannot be used 417 * as a callout device, which means we always have a carrier, 418 * because the master is. 419 */ 420 421 if (revents == 0) { 422 /* 423 * This code might look misleading, but the naming of 424 * poll events on this side is the opposite of the slave 425 * device. 426 */ 427 if (events & (POLLIN|POLLRDNORM)) 428 selrecord(td, &psc->pts_outpoll); 429 if (events & (POLLOUT|POLLWRNORM)) 430 selrecord(td, &psc->pts_inpoll); 431 } 432 433 tty_unlock(tp); 434 435 return (revents); 436 } 437 438 /* 439 * kqueue support. 440 */ 441 442 static void 443 pts_kqops_read_detach(struct knote *kn) 444 { 445 struct file *fp = kn->kn_fp; 446 struct tty *tp = fp->f_data; 447 struct pts_softc *psc = tty_softc(tp); 448 449 knlist_remove(&psc->pts_outpoll.si_note, kn, 0); 450 } 451 452 static int 453 pts_kqops_read_event(struct knote *kn, long hint) 454 { 455 struct file *fp = kn->kn_fp; 456 struct tty *tp = fp->f_data; 457 struct pts_softc *psc = tty_softc(tp); 458 459 if (psc->pts_flags & PTS_FINISHED) { 460 kn->kn_flags |= EV_EOF; 461 return (1); 462 } else { 463 kn->kn_data = ttydisc_getc_poll(tp); 464 return (kn->kn_data > 0); 465 } 466 } 467 468 static void 469 pts_kqops_write_detach(struct knote *kn) 470 { 471 struct file *fp = kn->kn_fp; 472 struct tty *tp = fp->f_data; 473 struct pts_softc *psc = tty_softc(tp); 474 475 knlist_remove(&psc->pts_inpoll.si_note, kn, 0); 476 } 477 478 static int 479 pts_kqops_write_event(struct knote *kn, long hint) 480 { 481 struct file *fp = kn->kn_fp; 482 struct tty *tp = fp->f_data; 483 struct pts_softc *psc = tty_softc(tp); 484 485 if (psc->pts_flags & PTS_FINISHED) { 486 kn->kn_flags |= EV_EOF; 487 return (1); 488 } else { 489 kn->kn_data = ttydisc_rint_poll(tp); 490 return (kn->kn_data > 0); 491 } 492 } 493 494 static struct filterops pts_kqops_read = { 495 .f_isfd = 1, 496 .f_detach = pts_kqops_read_detach, 497 .f_event = pts_kqops_read_event, 498 }; 499 static struct filterops pts_kqops_write = { 500 .f_isfd = 1, 501 .f_detach = pts_kqops_write_detach, 502 .f_event = pts_kqops_write_event, 503 }; 504 505 static int 506 ptsdev_kqfilter(struct file *fp, struct knote *kn) 507 { 508 struct tty *tp = fp->f_data; 509 struct pts_softc *psc = tty_softc(tp); 510 int error = 0; 511 512 tty_lock(tp); 513 514 switch (kn->kn_filter) { 515 case EVFILT_READ: 516 kn->kn_fop = &pts_kqops_read; 517 knlist_add(&psc->pts_outpoll.si_note, kn, 1); 518 break; 519 case EVFILT_WRITE: 520 kn->kn_fop = &pts_kqops_write; 521 knlist_add(&psc->pts_inpoll.si_note, kn, 1); 522 break; 523 default: 524 error = EINVAL; 525 break; 526 } 527 528 tty_unlock(tp); 529 return (error); 530 } 531 532 static int 533 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, 534 struct thread *td) 535 { 536 struct tty *tp = fp->f_data; 537 #ifdef PTS_EXTERNAL 538 struct pts_softc *psc = tty_softc(tp); 539 #endif /* PTS_EXTERNAL */ 540 struct cdev *dev = tp->t_dev; 541 542 /* 543 * According to POSIX, we must implement an fstat(). This also 544 * makes this implementation compatible with Linux binaries, 545 * because Linux calls fstat() on the pseudo-terminal master to 546 * obtain st_rdev. 547 * 548 * XXX: POSIX also mentions we must fill in st_dev, but how? 549 */ 550 551 bzero(sb, sizeof *sb); 552 #ifdef PTS_EXTERNAL 553 if (psc->pts_cdev != NULL) 554 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev); 555 else 556 #endif /* PTS_EXTERNAL */ 557 sb->st_ino = sb->st_rdev = tty_udev(tp); 558 559 sb->st_atimespec = dev->si_atime; 560 sb->st_ctimespec = dev->si_ctime; 561 sb->st_mtimespec = dev->si_mtime; 562 sb->st_uid = dev->si_uid; 563 sb->st_gid = dev->si_gid; 564 sb->st_mode = dev->si_mode | S_IFCHR; 565 566 return (0); 567 } 568 569 static int 570 ptsdev_close(struct file *fp, struct thread *td) 571 { 572 struct tty *tp = fp->f_data; 573 574 /* Deallocate TTY device. */ 575 tty_lock(tp); 576 tty_rel_gone(tp); 577 578 return (0); 579 } 580 581 static struct fileops ptsdev_ops = { 582 .fo_read = ptsdev_read, 583 .fo_write = ptsdev_write, 584 .fo_truncate = ptsdev_truncate, 585 .fo_ioctl = ptsdev_ioctl, 586 .fo_poll = ptsdev_poll, 587 .fo_kqfilter = ptsdev_kqfilter, 588 .fo_stat = ptsdev_stat, 589 .fo_close = ptsdev_close, 590 .fo_flags = DFLAG_PASSABLE, 591 }; 592 593 /* 594 * Driver-side hooks. 595 */ 596 597 static void 598 ptsdrv_outwakeup(struct tty *tp) 599 { 600 struct pts_softc *psc = tty_softc(tp); 601 602 cv_broadcast(&psc->pts_outwait); 603 selwakeup(&psc->pts_outpoll); 604 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0); 605 } 606 607 static void 608 ptsdrv_inwakeup(struct tty *tp) 609 { 610 struct pts_softc *psc = tty_softc(tp); 611 612 cv_broadcast(&psc->pts_inwait); 613 selwakeup(&psc->pts_inpoll); 614 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0); 615 } 616 617 static int 618 ptsdrv_open(struct tty *tp) 619 { 620 struct pts_softc *psc = tty_softc(tp); 621 622 psc->pts_flags &= ~PTS_FINISHED; 623 624 return (0); 625 } 626 627 static void 628 ptsdrv_close(struct tty *tp) 629 { 630 struct pts_softc *psc = tty_softc(tp); 631 632 /* Wake up any blocked readers/writers. */ 633 psc->pts_flags |= PTS_FINISHED; 634 ptsdrv_outwakeup(tp); 635 ptsdrv_inwakeup(tp); 636 } 637 638 static void 639 ptsdrv_pktnotify(struct tty *tp, char event) 640 { 641 struct pts_softc *psc = tty_softc(tp); 642 643 /* 644 * Clear conflicting flags. 645 */ 646 647 switch (event) { 648 case TIOCPKT_STOP: 649 psc->pts_pkt &= ~TIOCPKT_START; 650 break; 651 case TIOCPKT_START: 652 psc->pts_pkt &= ~TIOCPKT_STOP; 653 break; 654 case TIOCPKT_NOSTOP: 655 psc->pts_pkt &= ~TIOCPKT_DOSTOP; 656 break; 657 case TIOCPKT_DOSTOP: 658 psc->pts_pkt &= ~TIOCPKT_NOSTOP; 659 break; 660 } 661 662 psc->pts_pkt |= event; 663 ptsdrv_outwakeup(tp); 664 } 665 666 static void 667 ptsdrv_free(void *softc) 668 { 669 struct pts_softc *psc = softc; 670 671 /* Make device number available again. */ 672 if (psc->pts_unit >= 0) 673 free_unr(pts_pool, psc->pts_unit); 674 675 chgptscnt(psc->pts_uidinfo, -1, 0); 676 uifree(psc->pts_uidinfo); 677 678 knlist_destroy(&psc->pts_inpoll.si_note); 679 knlist_destroy(&psc->pts_outpoll.si_note); 680 681 #ifdef PTS_EXTERNAL 682 /* Destroy master device as well. */ 683 if (psc->pts_cdev != NULL) 684 destroy_dev_sched(psc->pts_cdev); 685 #endif /* PTS_EXTERNAL */ 686 687 free(psc, M_PTS); 688 } 689 690 static struct ttydevsw pts_class = { 691 .tsw_flags = TF_NOPREFIX, 692 .tsw_outwakeup = ptsdrv_outwakeup, 693 .tsw_inwakeup = ptsdrv_inwakeup, 694 .tsw_open = ptsdrv_open, 695 .tsw_close = ptsdrv_close, 696 .tsw_pktnotify = ptsdrv_pktnotify, 697 .tsw_free = ptsdrv_free, 698 }; 699 700 #ifndef PTS_EXTERNAL 701 static 702 #endif /* !PTS_EXTERNAL */ 703 int 704 pts_alloc(int fflags, struct thread *td, struct file *fp) 705 { 706 int unit, ok; 707 struct tty *tp; 708 struct pts_softc *psc; 709 struct proc *p = td->td_proc; 710 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 711 712 /* Resource limiting. */ 713 PROC_LOCK(p); 714 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 715 PROC_UNLOCK(p); 716 if (!ok) 717 return (EAGAIN); 718 719 /* Try to allocate a new pts unit number. */ 720 unit = alloc_unr(pts_pool); 721 if (unit < 0) { 722 chgptscnt(uid, -1, 0); 723 return (EAGAIN); 724 } 725 726 /* Allocate TTY and softc. */ 727 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 728 cv_init(&psc->pts_inwait, "ptsin"); 729 cv_init(&psc->pts_outwait, "ptsout"); 730 731 psc->pts_unit = unit; 732 psc->pts_uidinfo = uid; 733 uihold(uid); 734 735 tp = tty_alloc(&pts_class, psc); 736 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 737 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 738 739 /* Expose the slave device as well. */ 740 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit); 741 742 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 743 744 return (0); 745 } 746 747 #ifdef PTS_EXTERNAL 748 int 749 pts_alloc_external(int fflags, struct thread *td, struct file *fp, 750 struct cdev *dev, const char *name) 751 { 752 int ok; 753 struct tty *tp; 754 struct pts_softc *psc; 755 struct proc *p = td->td_proc; 756 struct uidinfo *uid = td->td_ucred->cr_ruidinfo; 757 758 /* Resource limiting. */ 759 PROC_LOCK(p); 760 ok = chgptscnt(uid, 1, lim_cur(p, RLIMIT_NPTS)); 761 PROC_UNLOCK(p); 762 if (!ok) 763 return (EAGAIN); 764 765 /* Allocate TTY and softc. */ 766 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO); 767 cv_init(&psc->pts_inwait, "ptsin"); 768 cv_init(&psc->pts_outwait, "ptsout"); 769 770 psc->pts_unit = -1; 771 psc->pts_cdev = dev; 772 psc->pts_uidinfo = uid; 773 uihold(uid); 774 775 tp = tty_alloc(&pts_class, psc); 776 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx); 777 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx); 778 779 /* Expose the slave device as well. */ 780 tty_makedev(tp, td->td_ucred, "%s", name); 781 782 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops); 783 784 return (0); 785 } 786 #endif /* PTS_EXTERNAL */ 787 788 int 789 posix_openpt(struct thread *td, struct posix_openpt_args *uap) 790 { 791 int error, fd; 792 struct file *fp; 793 794 /* 795 * POSIX states it's unspecified when other flags are passed. We 796 * don't allow this. 797 */ 798 if (uap->flags & ~(O_RDWR|O_NOCTTY)) 799 return (EINVAL); 800 801 error = falloc(td, &fp, &fd); 802 if (error) 803 return (error); 804 805 /* Allocate the actual pseudo-TTY. */ 806 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp); 807 if (error != 0) { 808 fdclose(td->td_proc->p_fd, fp, fd, td); 809 return (error); 810 } 811 812 /* Pass it back to userspace. */ 813 td->td_retval[0] = fd; 814 fdrop(fp, td); 815 816 return (0); 817 } 818 819 static void 820 pts_init(void *unused) 821 { 822 823 pts_pool = new_unrhdr(0, INT_MAX, NULL); 824 } 825 826 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL); 827